# Mining Every Last BitCoin?

I’m told that their is a total number of bitcoins that can be mined, 21 million bitcoins I’ve heard. I’ve heard that the more bitcoins that are mined there is a direct increases in the level of difficulty and in resources, required to mine more bitcoins.

I’ve heard many estimates from 10 years to 100 years to mine all 21 million bitcoins.

With the unknown variable of future increases in processing power, how could anyone make a educated guess as to how long it will take?

Additionally, if it is true that Moore’s law will be ending as we currently know it due to limitations in our current manufacturing methods of Processors, then this would lend even more weight to my theory that estimating the time of will take to mine all 21 million bitcoins is a guess, at best.

Please explain if I’m wrong and what I’m failing to understand about this, as I’m pretty new to crypto but eager to learn!

Cheers!

I’ve heard that the more bitcoins that are mined there is a direct increases in the level of difficulty and in resources, required to mine more bitcoins.

You have heard incorrectly. That is absolutely incorrect. The difficulty has nothing to do with how many Bitcoin have already been mined; all that matters for the difficulty is the average time between blocks for a sample of 2016 blocks.

I’ve heard many estimates from 10 years to 100 years to mine all 21 million bitcoins.

It is estimated that the block subsidy (which is what creates new Bitcoin) will reach 0 in 2140. The block subsidy will effectively be 0 long before that. It is impossible for all Bitcoin to be mined within 10 years as the hashrate required for that is too great.

With the unknown variable of future increases in processing power, how could anyone make a educated guess as to how long it will take?

Blocks are mined at a roughly fixed rate. The rate is fixed by the difficulty which adjusts every 2016 blocks. The difficulty adjusts so that it takes 10 minutes to find a block, on average. So if there is a massive increase in hashrate, the difficulty will increase as well so that blocks are still found 10 minutes apart.

Since we know how long it will take to mine blocks, on average, and we also know how many blocks it takes to mine all Bitcoin into existence (6,930,000 blocks), we can predict, roughly, when all Bitcoins will be mined.

• You said: “impossible for all bitcoin to be mined in 10 years...as the hash rate required is too great” .....if in 5 years from now, GPU/CPU power has an exponential leap above its normative growth, then we could see a large jump in the currently known and currently predicted hash rate. Thoughts? Feb 14, 2018 at 5:52
• Mining all blocks within 10 years requires ASIC hardware (note that Bitcoin is not mined on GPUs or CPUs anymore) to have exponential increases in hash power daily, for 10 years. There are 315360000 seconds in 10 years, and 6421000 blocks to be found in that time. That means that blocks would need to be found every 42 seconds, on average. In order to reach that now, the hashrate would need to be ~14 times what it currently is now.
– Ava Chow
Feb 14, 2018 at 6:04
• Then every 2016 blocks (so just over a day at 42 seconds a block) the difficulty will adjust. It can only adjust by a factor of 4 at most, so in order to counteract that, we need to quadruple the hash rate basically every day. That's pretty infeasible considering that new hardware needs to be built and setup, and then new technological enhancements need to be made to support that much computing power.
– Ava Chow
Feb 14, 2018 at 6:05
• Appreciate the robust and informative response! I guess I’m set on the belief that a new idea will emerge taking us beyond GPU, and ASIC mining, creating a day in which ASIC is ancient due to its slow hash rate compared to the next evolutionary advance. Feb 14, 2018 at 6:09
• Anything that comes after ASICs will just be "better ASICs". An ASIC is a generic term (much broader than CPU or GPU) that means "Application Specific Integrated Circuit" and any chip that is designed to mine Bitcoin (or do any other application) is, by definition, an ASIC. So unless this new advancement is not an integrated circuit (which I think is unlikely as it would mean a completely different method of computing which has no circuits), it will be an ASIC, just a better ASIC.
– Ava Chow
Feb 14, 2018 at 6:16